Chemical substances explosive characteristics

Professor Martel s book addresses specifically some of the more technical eispects of the risk assessment process, mainly in the areas of hazard identification, and of the consequence/effect analysis elements, of the overall analysis whilst where appropriate setting these aspects in the wider context. The book brings together a substantial corpus of information, drawn from a number of sources, about the toxic, flammable and explosive properties and effect (ie harm) characteristics of a wide range of chemical substances likely to be found in industry eind in the laboratory, and also addresses a spectrum of dangerous reactions of, or between, such substances which may be encountered. This approach follows the classical methodology and procedures of hazard identification, analysing material properties eind... 

The term Q is zero for the nonreaction R-H curve. These eqs are important in explosives theory. They permit correlation of the explosive characteristics of substances with other physical and chemical properties, and allow determination of the temperature and pressure conditions within the detonation zone... 

Physical chemistry. Identity and physico-chemical properties of the substance. This includes the structural formula of the chemical or the components of a mixture, melting point, boiling point, water and fat solubility, vapour pressure, partition coefficient and data on flammability and explosion characteristics. This involves a great deal of detailed analytical work all of which must be carried out to the highest standard, for instance using Good Laboratory Practice (GLP) in a quality assured laboratory. 

Synonyms and trade names acetic aldehyde, aldehyde, ethanol, ethylaldehyde Use and exposure Acetaldehyde is a highly flammable, volatile, colorless liquid with a characteristic and pungent odor. It is miscible in water. Exposure to acetaldehyde occurs during the production of acetic acid and various other industrial chemical substances—for instance, manufacture of drugs, dyes, explosives, disinfectants, phenolic and urea resins, rubber accelerators, and varnish. - - ... 

The physical, chemical and hazardous properties of a number of highly toxic or flammable substances that were in the past or being currently used in the warfare have been discussed in detail in several chapters in this book. Some of these compounds are further discussed under specific chapters, such as. Sulfur Mustards, Nerve Gases, Dioxin and Related Compounds and Napalm. These and many other compounds are in most cases grouped together in this book based on their chemical structures along with their toxic or flammable properties. Presented below is a brief discussion on various types of chemicals weapons developed for military applications. Explosive substances have been omitted from this section. They are discussed separately in this book under topics such as Explosive Characteristics of Chemical Substances, Nitro Explosives, Oxidizers and Organic Peroxides and also under specific title compounds in various chapters. 

The characteristics of a chemical or substance that would categorize it as a reactive material include (1) it reacts violently with water, (2) it forms potentially explosive mixtures with water, or (3) when mixed with water or other chemicals, it generates... 

Physical properties are important considerations in any study of accidents and emergencies. A substance may exhibit certain characteristics under one set of conditions of temperature, pressure, and composition. However, if the conditions are clianged, a once-safe operation may become a liazard by virtue of vulnerability to fire, explosion, or mpturing. To promote a better understanding of these effects, many of which are covered in Chapter 7, a brief rc iew of some key physical and chemical properties is provided in tliis and the next section. 

This question pertains to substances that will react with the oxygen in the atmosphere to form unstable peroxides, which in turn might explosively decompose if concentrated. Peroxide formation, or peroxidation, usually happens slowly over time, when a peroxideforming liquid is stored with limited access to air. Substances that are peroxide formers will often have an inhibitor or stabilizer added to prevent peroxidation. They are often not easily identifiable as peroxide formers using MSDSs or International Chemical Safety Cards. They are often identified by another characteristic, such as flammability, for storage and shipping purposes. 

Corrosivity is that characteristic of chemicals that exhibits extremes of acidity or basicity or a tendency to corrode steel. Such chemicals, used in various refining (treating) processes, are acidic and are capable of corroding metal such as tanks, containers, drums, and barrels. On the other hand, reactivity is a violent chemical change (an explosive substance is an obvious example) that can result in pollution and/or harm to indigenous flora and fauna. Such wastes are unstable under ambient conditions insofar as they can create explosions, toxic fumes, gases, or vapors when mixed with water. 

The characteristics of a chemical or substance that would categorize it as a reactive material include (1) it reacts violently with water, (2) it forms potentially explosive mixtures with water, or (3) when mixed widi water or other chemicals, it generates toxic gases, vapors or fumes in a quantity sufficient to present a danger to human health or the environment. Because water is the most common fire suppressant, the characteristic of reactivity is especially relevant since the application of water to eliminate or prevent the spread fires may be counterpro-ductive rather than helpful. Several categories of chemicals will be discussed from this standpoint however, several of these same chemicals also present additional hazards. 

Volatility or readiness with which a substance vaporizes, is an undesirable characteristic for military explosives. Explosives must be no more than slightly volatile at the temperature at which they are loaded or at the highest storage temperature. Excessive volatility often results in the development of pressure within the rounds of ammunition and separation of mixtures into their constituents. Volatility also affects chemical composition of the explosive resulting in the marked reduction in stability leading to an increase in the danger of handling. 

Copper is distinguished by several properties that contribute to its extensive use (I) a combination of mechanical workability with corrosion resistance lo many substances (2) excellent electrical conductivity, (3) superior thermal conductivity 14) effect as an ingredient of alloys to improve their physical and chemical properties (5) efficiency of copper and some of its compounds as catalysis for several kinds of chemical reaction (6) nonmagnetic characteristics, advantageous in electrical and magnetic apparatus and (7) nonsparking characteristics, mandatory for tools lor use in explosive atmospheres. There are additional attractions nf copper for many other applications. The metal would be used even more widely, hut... 

Another survey may be made based on the presence of an explosive atomic group. This survey is helpful for substances not specifically described in Bretherick s book. A table of atomic groups characteristic of explosive substances is presented on page XXXViii of the handbook or on page 42 of Safety of Reactive Chemicals 3. If the explosive atomic group is contained within a substance in question, the substance is probably explosive and it should be treated very carefully. Some companies that have already conducted preliminary evaluations of reactive chemicals will add the atomic group specific to unstable new substances to this table and use this information for the preliminary evaluation of additional substances. 

---